Blown gasket or Cracked head..need advise

[Gerry]

Hi Guys,

I have a 1989 2.4TD, with overheating problems on long distances ( 4-5hrs). I've had the radiator core replaced and the cooling system tested for leaks.

The report from the radiator repair shop is that water is getting through/to the water jacket???. They reckon the head gasket is blown or worse case the head cracked.

I've run the engine for a while with the rad cap off , but don't see any bubbles getting through, the oil cap has no moisture and the dip shows clean oil. No problems on daily driving.

Is there anyway of finding how bad the leak without removing the head. And if so is there anyway of sealing it, without blocking the radiator,if its a minor leak.

I'll be glad of any advise

Cheers

Gerry

[Koi]

Hi Guys,

I have a 1989 2.4TD, with overheating problems on long distances ( 4-5hrs). I've had the radiator core replaced and the cooling system tested for leaks.

The report from the radiator repair shop is that water is getting through/to the water jacket???. They reckon the head gasket is blown or worse case the head cracked.

I've run the engine for a while with the rad cap off , but don't see any bubbles getting through, the oil cap has no moisture and the dip shows clean oil. No problems on daily driving.

Is there anyway of finding how bad the leak without removing the head. And if so is there anyway of sealing it, without blocking the radiator,if its a minor leak.

I'll be glad of any advise

Cheers

Gerry

Past experience says the head is cracked, very very rare just for the gasket to go.
But strange you say you have had it running with the rad cap off, if so and the head was gone I would expect it to have been pumping coolant out the cap while it was off.
When my head went, the temp needle never moved, it run fine and I drove it around for two or three weeks before reparing it.
Only sure way is a pressure test, but either way gasket or head its got to come apart.

[Gerry]

Head Update- Still need advise

Follow up on Blown Gasket or Cracked Head................If I run the engine and get temperature up and remove the rad cap, there is air getting through, not alot, but it is blowing! I am loosing approx 1/2 a litre of coolant every day or so.

I plan to take the head off next week and have it tested. Is there anything I need to look for in particular, or can a good diesel mechanic sort it out???

Regards

Gerry

[marky]

The head usually cracks between the valves. Also check for corrosion at the top of the bores, These can be re-sleved in extreme circumstances, Its also worth replacing the water pump as well.

[dirtydog]

Past experience says the head is cracked, very very rare just for the gasket to go.
But strange you say you have had it running with the rad cap off, if so and the head was gone I would expect it to have been pumping coolant out the cap while it was off.
When my head went, the temp needle never moved, it run fine and I drove it around for two or three weeks before reparing it.
Only sure way is a pressure test, but either way gasket or head its got to come apart.

You mean I cant rely on just my temp gauge to tell me everything is ok?

[marky]

My head went & temp guage showed normal. Some have seen temp in the red when head went some have'nt

[stara]

the temp will only rise if it overheats, a cracked head will not necessarily cause overheating, what usually happens is the overpressurised cooling system dumps the coolant, or the engine burns it off, then, once the coolant gets too low, it will overheat, but as some people are aware of their coolant loss, it is kept topped up, and no overheating is encountered, on the other hand some people won't notice coolant loss, and they will get overheating when the coolant level becomes too low to cool the engine, however, if the coolant loss is sudden and enough coolant is lost in a small amount of time, then the temp sensor can become 'dry' and not show the remaining coolant temp. on top of this, the toyota temp gauge is not the most accurate.